Relationship between the thickness of the roof of glenoid fossa, condyle morphology and remaining teeth in asymptomatic European patients based on cone beam CT data sets

Differences in morphology of temporomandibular joint ankylosis of traumatic and infective origin

The aim of this study was to determine whether there are any differences in morphology between temporomandibular joint ankylosis (TMJA) of traumatic and infective origin. Cone beam computed tomography (CBCT) scans of 25 patients (28 joints) with TMJA of traumatic origin (trauma group) and 15 patients (15 joints) with TMJA of infectious origin (infection group) were included. The following morphological parameters were evaluated on multiple sections of the CBCT scans: lateral juxta-articular bone growth, residual condyle, residual glenoid fossa, ramus thickening, ankylotic mass fusion line, sclerosis of the ankylosed condyle and spongiosa of the glenoid fossa, and mastoid and glenoid fossa air cell obliteration. Lateral juxta-articular bone growth, juxta-articular extension of fusion, and the presence of normal medial residual condyle and residual glenoid fossa were exclusively found in post-traumatic TMJA. There were differences in ramus thickening (82.1% in trauma vs 53.3% in infection), sclerosis of the ankylosed condyle (100% in trauma vs 60% in infection), and sclerosis of the spongiosa of the glenoid fossa (100% in trauma vs 46.7% in infection) between the trauma and infection groups. Mastoid and glenoid fossa air cell obliteration was found more frequently in the infection group (mastoid obliteration: 23.1% in infection vs 4% in trauma; glenoid obliteration: 66.7% in infection vs 55.6% in trauma ). CBCT imaging can be helpful in differentiating between TMJA of traumatic and infectious origin.

Assessment of thickness of roof of the glenoid fossa in dentate, edentulous, and partially edentulous subjects using cone beam computed tomography (CBCT) - a retrospective study

OBJECTIVES

Studies have inferred a direct association between Temporomandibular joint disorders (TMD) and the integrity of the structures associated with it such as the Glenoid fossa thereby necessitating the requirement to measure the thickness of this oft ignored entity. This study was carried out to assess the thickness of the glenoid fossa roof in dentulous, edentulous, and partially edentulous subjects using archival Cone beam computed tomography (CBCT) images.

METHOD

Analysis of CBCT data of 120 joints from 60 adult subjects without signs and symptoms of TMD was carried out. The scans were grouped based on the dental status as dentulous, edentulous, and partially edentulous and additionally into two sets as those below and above 40 years of age. The distance between the superior and inferior cortices of the glenoid fossa was measured indicating the thickness of the roof of the glenoid fossa in the coronal and sagittal planes, by three independent observers. Analysis of Variance (ANOVA) and Tukey's post hoc test were used to compare the association between the mean thickness of the glenoid fossa and the dentition status. A p ≤ 0.05 was considered to be significant.

RESULTS

There was no significant association between the mean thickness of the glenoid fossa and the dentition of the study participants of all three groups, when assessed by the three observers, except the mean thickness on the right side in the sagittal section as measured by one observer. A thicker fossa was observed in edentulous subjects when compared to dentulous participants, and the difference was statistically significant (p = 0.035).

CONCLUSION

The thickness of the roof of the glenoid fossa demonstrated no association with the dental status of the study participants and no age or sex related differences were noted.

Relationship between the condyle morphology and clinical findings in terms of gender, age, and remaining teeth on cone beam computed tomography images

Aim: This study aimed to evaluate the relationship between clinical findings and some factors such as age, gender, and remaining teeth on the anatomy of the temporomandibular joint in order to diagnose normal variations from abnormal cases. Methods: In this cross-sectional study, cone-beam computed tomography (CBCT) images of 144 patients referring to Tabriz Dental School for various reasons were selected and evaluated. The different aspects of the clinical parameters and the morphology of the condyle were evaluated on coronal, axial, and sagittal views. The CBCT prepared using the axial cross-sections had been 0.5 mm in thickness. The sagittal cross-sections had been evaluated perpendicular to the lengthy axis of the condyle at a thickness of 1 mm and the coronal cross-sections had been evaluated parallel to the lengthy axis of the condyle at a thickness of 1 mm. Data were analyzed with descriptive statistical methods and t-test, chi-squared test, using SPSS 20. The significance level of the study was p < 0.05. Results: There was a significant relationship between the condyle morphology, number of the teeth, and mastication side (p = 0.040). There were significant relationships between the condyle morphology, age between 20-40, and occlusion class I on the all the three views (coronal, axial, sagittal) (p = 0.04), (p = 0.006), (p = 0.006). Also, significant relationships were found in the condyle morphology and location of pain according to age, the number of remaining teeth, and gender. (p = 0.046) (p = 0.027) (p = 0.035). Conclusion: There are significant relationships between the clinical symptoms and condyle morphology based on age, gender, and the number of remaining teeth. The clinical finding that has the most significant relationship between the condyle morphology, remaining teeth (9-16 teeth), all of the age range (20-80 year), and gender was mastication side.

Oval Type of Human Mandibular Condyle in Panoramic Radiographs of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Mandibular condyle is a prominent structure in the mandible, which forms the temporomandibular joint. An oval-shaped condyle is considered to be present with a normal temporomandibular joint and any morphological variation of the condyle is assumed to be pathologic in temporomandibular disorders. The aim of the study was to find out the prevalence of oval shaped mandibular condyle among orthopantomogram radiographs of patients visiting the tertiary care centre.

Methods

A descriptive cross-sectional study was performed among 752 condyles visiting a tertiary care center from November 29, 2021 to April 1, 2022. The ethical approval was taken from the Institutional Review Committee (Reference number: 184 (6-11) 078/079) before conducting the study. Convenience sampling was done. The radiographs were first examined and the observed morphological type of mandibular condyle was noted. Data analysis was done using Statistical Package for the Social Sciences version 22.0. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data.

Results

The prevalence of oval shaped mandibular condyles out of 752 condyles was 416 (55.32%) (51.77-58.87 at 95% Confidence Interval). The oval-shaped condyle on the right side was 205 (54.52%) and on the left side was 211 (56.12%).

Conclusions

The prevalence of oval shaped condyles among patients in this study was similar to the studies done in similar settings.

Keywords

condyle; mandible; Nepal; X-ray.

Degenerative bony changes in the temporal component of the temporomandibular joint - review of the literature

Temporomandibular joint (TMJ) changes are quite frequent in adults, but not all changes are degenerative. A high prevalence of bone alterations in the TMJs was reported by different research groups. Disturbed remodeling of bony articulating structures occurs because of overloading masticatory forces or because the mechanical loading in the area out-weighs the adaptive capacity of the TMJ structures. Although most of the degenerative TMJ alterations are identified at the level of the condylar process, a complete evaluation of the degenerative modifications encountered in the temporal TMJ region should not be forgotten as they are important for a comprehensive assessment and further management of the clinical situation. Several research groups have described osseous remodeling in the temporal component of the TMJ. Evidence is scarce for degenerative modifications at the level of the articular eminence and thickening of the roof of the glenoid fossa has been associated with osteoarthritis.

The impact of occlusal support on temporomandibular disorders: a literature review

Temporomandibular disorders are a multifactorial disease. Occlusal support and the number of teeth in dentition have significant effects on the masticatory system. The current study aims to review the role of occlusal support in association with findings of temporomandibular disorders. Data sources were PubMed, Web of Science and Google Scholar, with 1411 citations published over the period 1992–2019. The selection criteria stipulated that articles must have reported the association between the number of teeth, occlusal unit, occlusal support and temporomandibular disorders. A total of 15 full-text articles was finally accessed for eligibility in the current review. The studies on temporomandibular disorders were collected from various sources, including articles reporting temporomandibular disorder symptoms ( n=1), temporomandibular disorder signs ( n=5), temporomandibular joint osseous changes ( n=1), temporomandibular joint dysfunction using the Helkimo index ( n=2), and temporomandibular disorder classification ( n=6). Of these articles, significant associations were found between: the number of missing teeth and temporomandibular disorders ( n=5); the number of occlusal units and occlusal supports and temporomandibular disorders ( n=3); the position of the lost occlusal units and temporomandibular disorders ( n=1). Loss of the occlusal unit has more impact on temporomandibular disorders than the loss of posterior teeth. The total loss of unilateral occlusal support seems to be an aetiological factor for temporomandibular disorders, and maintenance of balanced posterior occlusal support has a role in the prevention and management of temporomandibular disorders.

Temporomandibular joint morphology in Korean using cone-beam computed tomography: influence of age and gender

OBJECTIVES

The purpose of this study was to investigate the condylar morphology and position of Koreans using cone-beam computed tomography (CBCT) images. Analyzing the mean values of this study with reference to left and right sides, gender, and age will help to understand the size of the condyle and glenoid fossa, condylar morphology, and temporomandibular joint (TMJ) symmetry for establishing the standard temporomandibular joint structures of Koreans and then design the standard temporomandibular joint prosthesis for Koreans.

RESULTS

There was no significant result in the condyle size, condyle axis angle, joint space, fossa depth, and mandibular body size between the left and right sides (p > 0.05). On the other hand, the mediolateral width of the condyle and mandibular body size show significantly different with the gender (P < 0.05). Also, significant differences were found in condyle size, joint space, fossa depth, and mandibular body size according to age groups (p < 0.05).

CONCLUSIONS

Condylar position and morphology vary according to side, age, and gender. The results of this study are expected to help in customizing a treatment for the patients who need TMJ reconstruction by predicting the TMJ morphology according to age and gender and design the standard temporomandibular joint prosthesis for the Koreans.

Morphological Assessment of TMJ Spaces, Mandibular Condyle, and Glenoid Fossa Using Cone Beam Computed Tomography (CBCT): A Retrospective Analysis

Background  The temporomandibular joint (TMJ) is included in the category of ginglymoarthrodial synovial joints. The mandibular condyle plays a vital part in the development of the craniofacial complex. Hence, the evaluation and assessment of the condylar volume and its morphology are of utmost importance.

Aim  The aim of this research was to use cone beam computed tomography (CBCT) imaging modality to evaluate the morphology of the mandibular condyle and glenoid fossa in a selected population and document any morphometric changes.

Setting and Design  It is an observational study.

Materials and Methods  A retrospective CBCT analysis was performed on 119 patients. The length, width, height, linear measurements of the joint spaces (anterior, posterior, and superior), volume of the condyle, and roof of glenoid fossa thickness were evaluated on both the left and right sides in both males and females.

Results  The height, width, and length of mandibular condyle were significantly increased in males on both sides. Except for the left anterior space, all other spaces were significantly larger in males. Overall, the volume of the condyles in males was significantly increased on both sides.

Conclusion  CBCT can be a valuable diagnostic aid in the evaluation of various dimensions, joint spaces, and condylar volume in different planes and thus, can be a useful predictor in the assessment of treatment outcomes of disorders affecting the TMJ.

The influence of mandibular condyle morphology on TMJ anterior dislocations

OBJECTIVES

The present study was designed to investigate the correlation between the bony morphology of the mandibular condyle and the occurrence of temporomandibular joint (TMJ) idiopathic anterior dislocation.

STUDY DESIGN

A comparative retrospective study was conducted among 14 patients presenting idiopathic anterior dislocations (study group) and 15 patients who did not suffer from any TMJ disorders (control group). All patients underwent a multidetector computed tomography scan demonstrating the full extent of their joints. The scans of 58 joints were reconstructed and analyzed by tools available in Dolphine3 software. Mandibular condyle size and volume were measured, and its shape was characterized.

RESULTS

Shape, width, length, height, and volume of the mandibular condyles did not differ statistically between the study and control groups.

CONCLUSION

Mandibular condyle morphology does not affect TMJ idiopathic anterior dislocation.

Morphometric evaluation of the temporomandibular joint on cone-beam computed tomography

INTRODUCTION

Evaluation of the temporomandibular joint (TMJ) pathologies with cone-beam computed tomography (CBCT) provides essential information about the bone structures of the TMJ. It is important to know the normal reference range when defining these pathologies. The aim of this study is to examine the morphometric and morphologic analyses of the bone structures of TMJ on the CBCT images in detail according to age, gender, and joint side.

MATERIAL AND METHODS

A total of 35 parameters related to the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint space were examined on the CBCT images. These parameters were compared with the joint sides and gender, and correlated with age.

RESULTS

Thirty-five parameters were evaluated. A statistically significant difference was found between genders in 22 parameters and joint sides in 6 parameters. When the correlation of parameters with age was examined; it was found that there was a very weak positive relationship in nine parameters, a weak positive relationship in one parameter, and a very weak relationship in the negative direction in two parameters.

CONCLUSION

In this study, the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint spaces, which are usually examined separately in the literature, were examined, and the normal reference range was determined for all these parameters. We think that these normal reference ranges will be useful for researchers interested in TMJ pathologies.

Volumetric and morphological analysis of condyle and glenoid fossa on computed tomography

AIM

The aim of this study was to evaluate temporomandibular joint (TMJ) condyle and glenoid fossa morphology with measurements on Computed Tomography (CT) and volumetric analysis using InVesalius software program.

MATERIALS AND METHODS

250 condyles in 125 patients (mean age: 40.64) was evaluated on CT. Length, width, and height of the condyle, condylar volume, the thickness of glenoid fossa (TGF), condyle surface area, anterior space (AS), superior space (SS), and posterior space (PS) were measured in this study. Two left and right sides of the jaw have been measured. Linear measurements were performed with the image analysis program (Image J, 1.4 v version, National Institutes of Health, Bethesda, MD). Volume and surface area measurements were performed with InVesalius software (CTI, Campinas, SãoPaulo, Brazil).

RESULTS

To compare the dimensions of the condyle between males and females, there was only a significant difference in left AS and SS and no significant difference was found between males and females in other measured factors. There was a significant difference between the age groups and left SS. A significant difference was also found between the age groups and condylar height, condyle surface area, and condylar volume on both right and left sides.

CONCLUSION

Evaluation of condylar morphology is important to assess the TMJ anomalies and bony changes. This study showed no significant differences between gender and all measured factors except in the left AS and SS. However, age factor had a major effect on the morphology.

2D-3D comparison of the temporomandibular joint in skeletal Class II versus Class I adults: A retrospective study

OBJECTIVE

To compare the temporomandibular joint (TMJ) morphological characteristics in people with Class II versus Class I sagittal skeletal relationship and to identify other factors that influence the TMJ dimensions.

MATERIAL AND METHODS

This cross-sectional and retrospective study evaluated 188 people divided into two groups, 92 cone-beam computed tomographies (CBCTs) and lateral radiographs (LR) of people with Skeletal class II relationship with Class II division 1 malocclusion versus 96 CBCTs and LR of people with Class I skeletal relationship and Class I malocclusion (controls). The CBCTs included people of both sexes, aged between 15 and 65 years old. The 3D Imaging Carestream Software was used to evaluate the condyle height and neck width, mediolateral and anteroposterior condyle dimensions, the shape of the glenoid fossa and condyle in the CBCTs. Likewise, the ANB angle, the Wits appraisal and other measurements were evaluated on LR. Besides, Mann-Whitney U, Chi² and multiple linear regression tests were performed. The significance level was set at P˂0.05.

RESULTS

The mediolateral and anteroposterior condyle dimensions were smaller in class II people (1.82mm and 0.29mm, respectively) than class I people (P<0.05). Likewise, height and neck width of condyle were smaller in class II people (0.73mm and 0.40mm, respectively) than class I people (P<0.05). Multiple linear regression identified mainly the ANB angle as a factor (P<0.05) that influenced the dimensions, decreasing the condyle dimensions in skeletal class II relationship.

CONCLUSIONS

People with skeletal class II relationship showed smaller condyle dimension values than class I people. A decrease in the dimensions of the eminence and the condyle could be expected when the ANB angle increases.

Temporomandibular Joints' Morphology and Osteoarthritic Changes in Cone-Beam Computed Tomography Images in Patients with and without Reciprocal Clicking-A Case Control Study

Background: Patients referred for orthodontic treatment often present symptoms of temporomandibular joints’ disorders (TMD), predominantly clicking. The objective was to analyze the morphology of the temporomandibular joints in cone-beam computed tomography (CBCT) images based on the presence of reciprocal clicking before orthodontic treatment. Methods: 105 participants took part in the study. 210 temporomandibular joints (TMJs) were allocated into one of two groups regarding the presence of reciprocal clicking. Morphology of condyle’s head, glenoid fossa, and articular eminence as well as condylar head position in the glenoid fossa and osteoarthritic changes in the area of the condylar head were examined for each TMJ in the CBCT images. Statistical analysis was performed with STATISTICA version 12.0. The following tests were performed: U-Mann Whitney, Kruskal-Wallis, t-Student, and chi-square. The statistical significance level was p = 0.05 for all the measurements included. Results: Significantly smaller condylar A-P dimension (p = 0.040) characterized temporomandibular joints with reciprocal clicking. Condyles were substantially more often positioned posteriorly (p = 0.043) and were significantly more often accompanied by subcortical cysts and pathologic osteoarthritic bone changes (p < 0.001). Conclusions: The early stages of internal derangements stay with alterations in morphology and position of TMJs as well as with the presence of osteoarthritic changes.

Morphology of the Temporomandibular Joints Regarding the Presence of Osteoarthritic Changes

(1) Osteoarthritis, the most common disease of the temporomandibular joints (TMJs), is diagnosed by clinical and radiographic examination. Cone beam computed tomography (CBCT) is a method of choice for the imaging of osteoarthritic changes. The objective was to compare the morphology of the TMJs in CBCT images regarding the number of the osteoarthritic changes diagnosed in the area of the condyle. (2) A total of 105 patients participated in the study; their 210 TMJs were allocated into one of three groups regarding the number of diagnosed osteoarthritic changes: 1 (none or 1 type), 2 (2 types), 3 (3 or more types). The morphology of the TMJ was examined for each TMJ in the CBCT images. Statistical analysis was performed with STATISTICA version 12.0. The statistical significance level was p = 0.05 for all the measurements included. (3) The articular surface flattening was the most common type of the osteoarthritic changes (90%). The condylar A-P dimension differed significantly among the groups (p = 0.0001). The bigger the number of osteoarthritic changes diagnosed in one joint, the smaller the condylar A-P dimension that was observed. (4) The temporomandibular joints’ osteoarthritic changes occur very often, even among asymptomatic patients. The increased number of osteoarthritic changes seems to have an impact on the condylar anteroposterior dimension.

Imaginology Tridimensional Study of Temporomandibular Joint Osseous Components According to Sagittal Skeletal Relationship, Sex, and Age

OBJECTIVE

To assess the temporomandibular joint (TMJ) osseous components morphology and the condyle position in patients with different sagittal skeletal relationships, sex, and age, using cone-beam computed tomography (CBCT).

METHODS

The CBCT images of 180 asymptomatic patients (60 class I, 60 class II, and 60 class III) were assessed retrospectively. Groups were also divided according to age (<40 years, n = 90; ≥40 years, n = 90) and sex (male, n = 90; female, n = 90). Right- and left-sided TMJ spaces, articular eminence inclination (AEI) and height (AEH), thickness of the roof of the glenoid fossa (TRGF) and the anteroposterior position of the condyle in glenoid fossa were evaluated. Differences were tested using the analysis of variance, Tukey and t-tests (P < 0.05).

RESULTS

For condylar position, no differences were found between sex and age groups, but spatial differences existed among skeletal classes. Significant differences were found between the right and left angular position in patients with malocclusion. Class II individuals presented lower anterior articular spaces. The condyle-glenoid fossa relationship presented a moderate correlation of bilaterality. The AEI and AEH were significant lower in class III individuals and class I patients presented the lowest values for TRGF. The values of AEH, TRGF and of all joint spaces of males were higher. In individuals over the age of 40 years, the AEI and AEH measurements were significant greater.

CONCLUSION

Sagittal skeletal relationships have a significant effect on condyle position, AEI, and AEH. The eminence inclination and height and TRGF are influenced by sex and age.

Comparison between Glenoid Fossa Roof Thickness in TMD and non-TMD Patients, a CBCT Study

Statement of the Problem

Various pathologic conditions can affect the thickness of the roof of glenoid fossa (RGF). The relationship between the RGF thickness and temporomandibular joint disorder (TMD) is not explicitly investigated. Considering the changes in RGF thickness, as a radiographic sign for TMD diagnosis, the phenomenon may necessitate specific treatment and may influence the treatment course and results.

Purpose

This research was designed to examine the relationship between TMD and RGF thickness changes compared to non-TMD group.

Materials and Method

In this cross sectional analytic research CBCT images of 70 TMD patients (140 joints) and 70 non-TMD individuals (140 joints) as control group were evaluated for thickness of RGF and presence of discontinuity in RGF. The distance between superior and inferior cortex of glenoid fossa was measured as RGF thickness. Inability to follow the course of cortex in any given image was considered as discontinuity. T-test, Chi-square and odds ratio (OR) were used for statistical analysis. In this study, p< 0.05 was considered meaningful.

Results

The mean thickness of RGF in our non-TMD samples was 1.12 mm. RGF thickness was significantly increased in TMD patients compared non-TMD group (p= 0.00). This value was also greater in males. On the other hand, TMD patient showed a higher incidence of discontinuity in RGF, in comparison with non-TMD patients (p= 0.006).

Conclusion

The increased thickness of RGF can be considered as a sign of TMD, which may help in diagnosis of TMD. It seems that there is a direct relationship between TMD and discontinuity of RGF.

Spatial analysis of mandibular condyles in patients with temporomandibular disorders and normal controls using cone beam computed tomography

OBJECTIVES

The aim of the study is to investigate the condylar position and its relation to articular eminence and axial condylar angle in temporomandibular joint disorder (TMD) patients and in normal controls using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT temporomandibular joint (TMJ) images of 70 participants (38 males and 32 females, mean age 26.4 years) were analyzed. They were divided into control group (including 35 subjects) and study group (including 35 subjects). Linear measurements of joint space and condyle determined the condylar position of each TMJ. Articular eminence height and inclination were also measured with axial condylar angle to determine its relation to condylar position. Independent and paired sample t-test was applied to compare between the groups and TMJ sides of the same group at significance level of 0.05.

RESULTS

Statistical significant differences were found between males and females of both groups regarding superior joint space (SJS), lateral joint space, A-P, and M-L condyle distance (P < 0.05). SJS, medial joint space (MJS), and eminence angle were greater (P < 0.01) in male's joints with TMD with flatter axial condylar angle (P < 0.05), when compared with normal TMJ counterpart. Females TMJs showed significantly higher values of MJS of affected side when compared with normal counterpart with flatter axial condylar angle (P < 0.05).

CONCLUSION

Superior and MJS parameters were the ones that showed significant differences between affected and nonaffected joints. The mean axial condylar angle was smaller in joints with abnormal TMJ. This indicates that the condyles of the affected joints may rotate inward.

Correlation between temporomandibular joint morphometric measurements and gender, disk position, and condylar position

OBJECTIVE

The aim of this study was to correlate the morphometric measurements of the temporomandibular joint, including condylar size, joint space, and articular eminence size, with gender, disk position, and condylar position by using magnetic resonance imaging.

STUDY DESIGN

Overall, 93 patients were evaluated (31.2% males and 68.8% females; age 18-81 years; mean age 41 years). Condylar size (D1), joint space (D2), and eminence size (D3) were measured. Correlations with gender, disk position, and condylar position were calculated.

RESULTS

A statistically significant correlation was found between D2 and gender, with the joint space being significantly larger in the male group (P = .05). There were correlations between D2 and the position of the disk and the position of the condyle (P ≤ .05).

CONCLUSIONS

The results indicate a correlation between male gender and larger joint space. In addition, we found that the joint space size influences the articular disk and condyle position, which can cause disk displacement.

Correlation between temporomandibular joint temporal component pneumatization and morphology: analysis by cone beam computed tomography

The aim of this study was to evaluate whether a correlation exists between temporal bone pneumatization and the morphology of the articular eminence and glenoid fossa. A sample of 100 cone beam computed tomography scans was used, for a total of 200 temporomandibular joints (TMJ). Paracoronal and parasagittal images of the TMJ were evaluated by two examiners. For all TMJ, pneumatization was classified in the mid-lateral direction using a score of 0 or 1, and in the anteroposterior direction using a score ranging from 0 to 3. The inclination and height of the articular eminence and the thickness of the roof of the glenoid fossa were obtained. Pneumatization was found in the mid-lateral direction in 83.5% of the cases and in the anteroposterior direction in 88%. The age of the patient and side did not influence the prevalence or degree of pneumatization (P=0.051-0.953), but female patients showed more pneumatization in the mid-lateral direction than male patients (P=0.014). The presence of pneumatization did not affect articular eminence and mandibular fossa morphology. It is concluded that the presence and extent of pneumatization of the TMJ temporal component does not affect its morphology. However, professionals should be aware of the high prevalence of pneumatization and take this into account when performing TMJ assessment.

Tissue Engineering for the Temporomandibular Joint

Tissue engineering potentially offers new treatments for disorders of the temporomandibular joint which frequently afflict patients. Damage or disease in this area adversely affects masticatory function and speaking, reducing patients' quality of life. Effective treatment options for patients suffering from severe temporomandibular joint disorders are in high demand because surgical options are restricted to removal of damaged tissue or complete replacement of the joint with prosthetics. Tissue engineering approaches for the temporomandibular joint are a promising alternative to the limited clinical treatment options. However, tissue engineering is still a developing field and only in its formative years for the temporomandibular joint. This review outlines the anatomical and physiological characteristics of the temporomandibular joint, clinical management of temporomandibular joint disorder, and current perspectives in the tissue engineering approach for the temporomandibular joint disorder. The tissue engineering perspectives have been categorized according to the primary structures of the temporomandibular joint: the disc, the mandibular condyle, and the glenoid fossa. In each section, contemporary approaches in cellularization, growth factor selection, and scaffold fabrication strategies are reviewed in detail along with their achievements and challenges.

Morphometric analysis for evaluating the relation between incisal guidance angle, occlusal plane angle, and functional temporomandibular joint shape variation

OBJECTIVE

The correlations between morphology of the temporomandibular joint structure, the anterior guidance angle, and occlusal plane were investigated.

MATERIALS AND METHODS

A cone beam computed tomography analysis was performed in 158 patients (86 women and 72 men). 3D software was employed to obtain the coordinates of the shape of the incisal guidance angle, occlusal guidance angle, articular fossa, and mandibular condyle. Generalized Procrustes analysis including principal components analysis (PCA) were performed and produced principal components (PCs) scores of each shape and their centroid size (CS).

RESULTS

A significant Pearson correlation coefficient of 0.3451 (p < .001) was observed between the incisal guidance angle and occlusal plane. The CS also showed a correlation with the incisal guidance angle, but not with the occlusal plane angle. The PCA results revealed that there were no significant correlations between the temporomandibular joint structure (TMJ) shape (fossa and condyle) and the incisal guidance angle.

CONCLUSIONS

Incisor guidance angle and occlusal plane angle were correlated. In addition, there was a correlation between CS and incisal guidance angle. In the PCA, It can be concluded that the size is more related to the incisor guidance angle than the morphological factors of the constituent components of the TMJ.

Temporomandibular condylar morphology in diverse maxillary-mandibular skeletal patterns: A 3-dimensional cone-beam computed tomography study

BACKGROUND

The authors evaluated the morphology and symmetry of the temporomandibular joint in participants with normodivergent and hyperdivergent skeletal class I, II, and III patterns.

METHODS

A total of 80 participants were divided into 4 groups on the basis of their sagittal and vertical skeletal patterns. Cone-beam computed tomographic images were used to evaluate the condyle-fossa relationship and the morphology and symmetry of the mandibular condyle. One-way analysis of variance and Tukey post hoc tests were used to compare the mean values among the different groups.

RESULTS

Participants with class II hyperdivergent patterns had the smallest anteroposterior (mean [standard deviation {SD}], 4.4 [1.6] millimeters) and mediolateral (10.5 [3.0] mm) condylar process widths among all 4 groups. The mean (SD) axial condylar angle was flatter in patients with class III hyperdivergent patterns (19.8° [5.1°]) compared with the other groups. The mean (SD) anteroposterior differences of the condylar processes (2.9 [1.4] mm) in patients with class III hyperdivergent patterns were the greatest in all 4 groups.

CONCLUSION

Participants in the group with class II hyperdivergent patterns have a smaller and narrower condyle compared with the other groups measured. Asymmetry was found among all groups, with participants with skeletal class III patterns having the most asymmetry. The most common condylar morphology in all groups examined was convex.

PRACTICAL IMPLICATIONS

These results support the concept that morphology and symmetry of the temporomandibular joint varies in different skeletal patterns, presumably as an adaptive response to functional demands.

Radiologic correlation between the thickness of the roof of the glenoid fossa and that of the bony covering of the superior semicircular canal

OBJECTIVES

Dehiscence of the superior semicircular canal (SSC) has been associated with alteration of the temporomandibular joint, although data explaining this association are lacking. The present study examined the correlations between the presence of dehiscences and thickness of the bone covering the SSC and the roof of the glenoid fossa (RGF).

STUDY DESIGN

Computed tomography was used in a cross-sectional analysis of the presence of dehiscences and thickness of the bone overlying the SCC and RGF in 156 temporal bones of 78 patients. The correlations of the presence of dehiscences in the SSC and ipsilateral RGF and the thickness of bone covering the SSC and RGF were analyzed by using the χ² or Fisher's exact test. The relationship between the thickness of the bone overlying the SCC and RGF was analyzed by using the Spearman correlation coefficient and the Kruskal-Wallis test. The relationship between the thickness of the RGF and the covering of the SCC and patient age and gender was analyzed with the general linear model.

RESULTS

Significant correlations were found between the presence of dehiscences and thickness of the bone overlying the SSC and RGF (P < .001).

CONCLUSIONS

There is a morphologic relationship between the structure of the SSC and RGF.

Comparison of Morphologic Parameters of Temporomandibular Joint for Asymptomatic Subjects Using the Two-Dimensional and Three-Dimensional Measuring Methods

The differences of temporomandibular joint (TMJ) morphologic parameters by using two-dimensional (2D) and three-dimensional (3D) measuring methods were compared. Ten asymptomatic subjects (26.75 ± 4.89 years) were randomly recruited. The 3D models of the maxilla, mandible, and teeth were reconstructed according to cone-beam computed tomography (CBCT) image data. The morphologic parameters of TMJs were measured by the 2D CBCT measuring method (group A) and the 3D reconstruction model measuring method (group B), respectively. The morphologic parameters in each group were assessed by paired samples t-test, and the statistical significance was achieved when p < 0.05. The horizontal condylar angle (HCA), sagittal ramus angle (SRA), medial joint space (MJS), lateral joint space (LJS), superior joint space (SJS), and anterior joint space (AJS) in group A were significantly smaller than those in group B (p < 0.05). The HCA on the left side was significantly smaller than that on the right side in group A (p < 0.05). However, all the morphologic parameters in group B were not significantly different between left and right sides. In conclusion, there were significant differences for the morphologic parameters of TMJ measured on 2D CBCT and 3D models. 3D measuring method should be used for the detection of TMJ morphology in clinical practice.

[Research on condylar morphology in patients with prolonged unilateral posterior teeth loss with cone beam computed tomography]

OBJECTIVE

This study aimed at using cone beam computed tomography (CBCT) to study the influence ofprolonged unilateral posterior teeth loss on bilateral condylar morphology.

METHODS

The CBCT images of 30 patients withprolonged unilateral posterior teeth loss and 30 healthy people as controls were corrected. Mimics 15.0 software was used tomeasure volume, area, distance, and bone density of condyle. The results were statistically analyzed.

RESULTS

The volumeand bone density of condylar head and the entire condyle on missing teeth side were less than the contralateral side (P<0.05).The area and bone density of condylar transverse plane were greater than the contralateral side (P<0.05).

CONCLUSION

After prolonged unilateral posterior teeth loss, adaptive reconstruction occurs in the bilateral condyles, and condyle of missing teethside is smaller than the contralateral side.

Temporomandibular joint diagnostics using CBCT

The present review will give an update on temporomandibular joint (TMJ) imaging using CBCT. It will focus on diagnostic accuracy and the value of CBCT compared with other imaging modalities for the evaluation of TMJs in different categories of patients; osteoarthritis (OA), juvenile OA, rheumatoid arthritis and related joint diseases, juvenile idiopathic arthritis and other intra-articular conditions. Finally, sections on other aspects of CBCT research related to the TMJ, clinical decision-making and concluding remarks are added. CBCT has emerged as a cost- and dose-effective imaging modality for the diagnostic assessment of a variety of TMJ conditions. The imaging modality has been found to be superior to conventional radiographical examinations as well as MRI in assessment of the TMJ. However, it should be emphasized that the diagnostic information obtained is limited to the morphology of the osseous joint components, cortical bone integrity and subcortical bone destruction/production. For evaluation of soft-tissue abnormalities, MRI is mandatory. There is an obvious need for research on the impact of CBCT examinations on patient outcome.

Assessment of condyle and glenoid fossa morphology using CBCT in South-East Asians

Introduction

Proper imaging allows practitioners to evaluate an asymptomatic tempormandibular joint (TMJ) for potential degenerative changes prior to surgical and orthodontic treatment. The recently developed cone-beam computed tomography (CBCT) allows measurement of TMJ bony structures with high accuracy. A study was undertaken to determine the morphology, and its variations, of the mandibular condyle and glenoid fossa among Malay and Chinese Malaysians.

Methods

CBCT was used to assess 200 joints in 100 subjects (mean age, 30.5 years). i-CAT CBCT software and The Mimics 16.0 software were employed to measure the volume, metrical size, position of each condyle sample and the thickness of the roof of the glenoid fossa (RGF).

Results

No significant gender differences were noted in thickness of the RGF and condylar length; however condylar volume, width, height and the joint spaces were significantly greater among males. With regards to comparison of both TMJs, the means of condylar volume, width and length of the right TMJ were significantly higher, while the means of the left condylar height and thickness of RGF were higher. When comparing the condylar measurements and the thickness of RGF between the two ethnic groups, we found no significant difference for all measurements with exception of condylar height, which is higher among Chinese.

Conclusion

The similarity in measurements for Malays and Chinese may be due to their common origin. This information can be clinically useful in establishing the diagnostic criteria for condylar volume, metrical size, and position in the Malaysian East Asians population.

Articular eminence inclination, height, and condyle morphology on cone beam computed tomography

Aim. The aim of the present study was to examine the relationship between articular eminence inclination, height, and thickness of the roof of the glenoid fossa (RGF) according to age and gender and to assess condyle morphology including incidental findings of osseous characteristics associated with osteoarthritis (OA) of the temporomandibular joint (TMJ) using cone beam computed tomography (CBCT). Materials and Methods. CBCT images of 105 patients were evaluated retrospectively. For articular eminence inclination and height, axial views on which the condylar processes were seen with their widest mediolateral extent being used as a reference view for secondary reconstruction. Condyle morphology was categorized both in the sagittal and coronal plane. Results. The mean values of eminence inclination and height of males were higher than those of females (P < 0.05). There were significant differences in the RGF thickness in relation to sagittal condyle morphology. Among the group of OA, the mean value of the RGF thickness for “OA-osteophyte” group was the highest (1.59 mm), whereas the lowest RGF values were seen in the “OA-flattening.” Conclusion. The sagittal osteoarthritic changes may have an effect on RGF thickness by mechanical stimulation and changed stress distribution. Gender has a significant effect on eminence height (Eh) and inclination.